Since that contest was mentioned only in this forum and mainly on that particular thread, this didn't get much attention, but if this were a larger scale event, there would be legal repercussions against a sponsor backing out like this, and also going forward all the funds should be secured by the organizer long before the event is concluded for the benefit of the participants...
It does not need to be a larger scale event. The problem here is that the forum is in limbo, the members are from very different countries and we are not identified, but in my country, and I'm sure it's not the only one, you could be sued for something like that, it's about 1.500€.